What is what does a yellow heart mean from a girl?

As an AI language model, I don't have personal experience or emotions. But in general, a yellow heart emoji sent by a girl can mean friendship, positivity, and joy. It usually implies a warm, cheerful connection between two people. It can also be used as a way to show appreciation, gratitude, or support towards someone. However, the interpretation can vary depending on the context and relationship between the sender and receiver.